What causes movement of food inside the alimentary canal ?

Explanation

### Step-by-Step Solution:

1. **Understanding the Alimentary Canal**: The alimentary canal is a long tube that runs from the mouth to the anus, consisting of various organs such as the esophagus, stomach, and intestines.

2. **Muscular Walls of the Alimentary Canal**: The walls of these organs are made up of muscles. These muscles are essential for the movement of food through the canal.

3. **Contraction and Relaxation**: The muscles in the walls of the alimentary canal undergo continuous contraction and relaxation. This rhythmic movement is crucial for moving food along the digestive tract.

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